有序多孔SiOC陶瓷的直写成型和机械性能调控研究

Porous SiOC ceramics, which can be with low-density, high-specific properties, and meet the demand of practical applications including catalyst supports, filters for high temperature separations, membrane supports for hydrogen separation, flue gas cleaning, lithium battery anodes, and insulation materials has become one of the hotspots for the research in the field of functional material in recent years. The performance of SiOC ceramics is depended on the coordination of celluer structures and microstructures; however, the forming difficulty is always one of the restrictions. Additive manufacturing of SiOC ceramics give the opportunity to created lightweight ceramic architectures composed of open-cell porous struts. Therefore, based on the modification of preceramic polymer, architected cellular SiOC ceramics will be prepared by direct ink writing. Linked with the rheological characteristics, and any other properties of the preceramic polymer affected by filler absorption, the effect of macrostructure and microstructure on mechanical property will be investigated. The phase structures and the mechanical properties will be influenced by pyrolysis processing. The relationship between polysiloxane preceramic polymer molecular structures and their rheology will also be discussed. Moreover, SiC, SiO2, C nanopowders and carbon fiber, graphene will be used as fillers to preceramic polymers, the effects to the ink rheology, direct writing ability, and the related microstructures will be analyzed. The scientific questions are crucial considered: the effect of architected cellular structure on the mechanical properties for SiOC porous ceramics and their physical mechanism; the inner relation between fillers’ intrinsic type, shape, quantity and the mechanical properties or mechanical temperature stability. It is expected to achieve high-performance architected cellular SiOC ceramics with controlled cellular structures and enhanced mechanical properties. Moreover, the related results of this research have important academic significance and practical applications.

多孔SiOC陶瓷是一种很好的轻质、耐高温材料，在催化、吸附、锂电、绝缘、过滤、传感等领域都展示出了应用潜质。其性能取决于SiOC陶瓷的宏观孔结构和微观结构的协同效应。然而陶瓷宏观结构的有效制备一直是个难题，以直书写为代表的增材制造技术可成型跨尺度、自支撑的复杂三维结构，为此提供了研究契机。本项目拟通过基于先驱体的直写成型技术及热处理工艺分别调控SiOC陶瓷的宏观孔结构与微观结构，阐明聚硅氧烷先驱体改性与其流变性、光固性和热解性的内在关系，探讨SiOC陶瓷宏观孔结构和微观结构在其机械性能中所起的关键作用；并利用硅系和碳系填料改善先驱体的流变性能，系统分析填料的种类、形态和分布及其对有序大孔结构、分子结构和相结构的影响，达到调控多孔SiOC陶瓷机械性能的目的。重点解决的关键科学问题是：网格结构对有序多孔SiOC陶瓷机械性能的影响规律；微尺度下填料对其机械性能及机械热稳定性的增强机制。

多孔SiOC陶瓷因其组分和结构的可设计性，同时展现出高的热稳定性与优异的机械性能，因此在很多领域都展示了应用潜质。其性能取决于SiOC陶瓷的宏观孔结构和微观结构的协同效应。本项目立足于聚硅氧烷先驱体的流变行为，利用直书写增材制造技术实现了SiOC陶瓷宏观孔结构的有效控制，开展了陶瓷结构与机械性能的关联研究，包括（1）浆料流变性、挤出特性和有序多孔SiOC陶瓷精密成型方法，（2）先驱体填料设计和调控方法，揭示了填料网络对SiOC材料模量的影响。这些研究为SiOC宏微观结构的精细调制及其功能化应用提供了途径。共发表了6篇SCI论文，相关会议分组报告6次，获得3项国家发明专利授权。